Waiting for test-run completion

It's difficult to use the python client for test-run completion. 
One needs to write a bash script that parses the stdout coming out from various commands:
- the one that schedules the job (to extract the job id)
- one that enquires the state of the job (to extract its status)
This cannot be done with python if only, because start_test_run does not return the job id (it only prints it out). 
Since anyone using this client will be interested in knowing when the job is finished, i thought I propose to enable it at the very root and propose this change.

Ok, I think that there is two cases(at least) when this could happen:
 1) Backend has lost all the tokens during server update/restart (
 2) Another api client has already request a new token using refresh token(frontend is currently using the same token so it might have requested a new token when python client is still trying using the old one)